The field of art to which this invention pertains is water-soluble polymers.
In certain industrial applications, it is desirable to suspend solids in aqueous fluids and then to allow the solids to settle out of the fluids. This can be done by using a water-soluble polymer to increase the viscosity and to thicken the fluid so that the solids will be suspended, and then to lower the viscosity so that the solids will drop out of suspension. This lowering of viscosity is accomplished by using "a breaker", which acts on the water-soluble polymer to reduce its molecular weight and to thin the fluid in which it is dissolved.
The breaking of gels or thickened aqueous fluids has been accomplished by using a variety of techniques, such as by the degradative action of acids, enzymes or mild oxidizing agents. In U.S. Pat. No. 4,464,268, sodium hypochlorite is described as being a drastic treating agent for degrading water-soluble polymers. Ammonium and alkali metal persulfates in combination with a tertiary amine are disclosed as being suitable as breaker systems for high viscosity fluids. The use of lithium hypochlorite as a breaker material is described in the Oil and Gas Journal, Dec. 12, 1983, pp. 96 to 101.
There is a constant effort to develop improved breaker systems which will degrade natural and synthetic polymers efficiently at ambient temperatures.